For inks, paints, coatings, adhesives, and the like, binder resins are used in order to improve pigment dispersion and adhesion performance. The polymer material used as the binder resin generally includes an acrylic resin, a vinyl-based resin, a urethane-based resin, and the like.
Among them, the vinyl chloride-based resin can be obtained in the form of fine particles by using a vinyl chloride monomer alone, or mixing a mixture of a vinyl chloride monomer and another comonomer that is copolymerizable therewith, a suspending agent, a buffer, a polymerization initiator, and the like, and then drying a polyvinyl chloride-based resin slurry produced by a suspension polymerization method.
Specifically, a vinyl chloride-based resin can use vinyl chloride, unsaturated carboxylic acid, and vinyl acetate as monomers, and has excellent adhesiveness to a metal material such as iron and aluminum, so it has been widely used in fields of ink binders and adhesives.
However, when a vinyl chloride-based resin containing a carboxylic acid is transported or stored for a long time under a high temperature and high humidity environment, there is a problem that the resin color is changed into pink or red from the original white color. During transportation or storage, if the resin color is changed depending on surrounding environmental conditions, not only will the commercial value of the resin be lost, but also the molecular structure is changed, and thereby several physical properties which are importantly evaluated in the field where resin is used, such as adhesiveness, solubility, transparency, and the like, can be deteriorated.
Thus, studies are needed for a vinyl chloride-based resin which exhibits good processability due to excellent solubility in a solvent, can implement excellent transparency in products produced, and improves the glossiness of a coating film when used as an ink binder, thereby being capable of being used as a high-quality adhesive and ink binder.